Disposable serving tray

ABSTRACT

Disposable serving trays suitable for serving snacks and dinners to airplane passengers have separately formed portions of a very thin flexible, thermoplastic sheet material shaped to that such portions may be stacked to occupy a minimal volume and are quickly stiffened to permit their use by slidably or adhesively attaching to the under surface thereof a suitable stiffening element, such as a sheet of chipboard. In one form of the invention, the stiffening member is slidably received in channels on opposite sides of the bottom of the tray and in a modified form the upper surface of the stiffening member and the lower surface of the tray are each coated with a dry, nontacky, pressure-sensitive adhesive which adheres to a similar coated surface on contact therewith.

United States Patent 1 3,567,067

[72] Inventor Hugh R. Weiss 3,080,997 3/1963 Brown 220/97'C-X Montclair, NJ. 3,099,567 7/1963 Wallace et al. 229/2.5-X

[21] Appl. No. 791,952 3,122,265 2/1964 Innis 220/97 [22] Filed Jan. 17, 1969 3,191,796 6/1965 Schwartz et alm. 220/97-D [45] Patented Mar. 2, 1971 3,240,610 3/1966 Cease 220/97-X [73] Assignee The Pantasote Company of New York, Inc. 3,344,974 10/1967 Bostrom 220/97-F New York, N.Y.

[54] DISPOSABLE SERVING TRAY 9 Claims, 8 Drawing Figs. [52] US (I 220/71, 206/72, 229/25 [51] Int. Cl. 865d 7/44, B65d 11/22 [50] Field ofSeu-ch 220/71,69,

3,013,656 12/1961 Murphy, Jr.

Primary Examiner-Raphael M. Schwartz Attorney-- Medert & Te Grotenhuis 1 board. In one form of the invention, the stiffening member is slidably received in channels on opposite sides of the bottom of the tray and in a modified form the upper surface of the stiffening member and the lower surface of the tray are each coated with a dry, nontacky, pressure-sensitive adhesive which adheres to a similar coated surface on conta therewith.

PATENT EDHAR 2|97l I I 3561067 SHEET1UF2 INVENTOR.

HUGH R; WEISS ATTOR NEYS PATENTED me am SHEET 2 OF 2 FIG. 8

ll 30 Fl G. 7

INVENTOR. HUGH R. WEISS MM 2 7e 0M ATTORNEYS DISPOSABLE SERVING TRAY The present invention relates to a disposable plastic tray, and particularly to a tray suitable for serving aircraft meals and snacks to customers. Trays for serving snacks, dinners and lunches to customers on aircraft and other vehicles must be relatively strong or stiff and must be stackable so that one tray intertits over another to occupy minimum volume. Heretofore, such trays have been prepared of heavy gauge, relatively rigid thermoplastic material, such as rigid or only slightly plasticized polyvinylchloride, vinyl styrene and the like, the heavy gauge being required to provide the necessary stiffness. Trays made of rigid, expanded plastic, such as foamed, rigid polystyrene to provide requisite stiffness and rigidity are found to occupy much too great a volume for economics of airplane travel and trays of unfoamed plastic material of sufficient thickness to provide requisite stiffness have excessive weight. In both cases the trays are unduly expensive because of the volume of expensive plastic material used therein.

It is an object of the present invention to provide trays which are especially suitable for use on aircraft where weight and space are both at a premium, which will stack to occupy relatively small volume, and which may be made of very thin plastic material and yet which are sufficiently stiff to be handled and to support food thereon without appreciable flexure.

Another object of the present invention is to provide serving trays which may be made of plastic material of the order of .005 or .006 inch in thickness and which may be stacked together prior to use in such a manner that a large number occupy only a relatively small space and which are of substantially lower cost and use substantially less thermoplastic resin than was used in trays of equivalent size heretofore.

The above and other objects will be apparent from the following description of the invention as illustrated by the accompanying drawings, in which:

FIG. 1 is a perspective view of the tray embodying the present invention;

FIG 2 is a perspective view of the inverted tray of FIG. 1, showing a removable stiffening member,.such as chipboard, partially removed from the tray;

FIG. 3 is a sectional view on the line 3-3 of FIG. 1 through a portion of the tray of FIG. 1;

FIG. 4 is a sectional view through the tray of FIG. 1 taken on the line 4-4 of FIG. 1;

FIG. 5 is an expanded stack of three trays illustrating the manner in which the trays may be superimposed upon each other, with the trays separated from each other in order to show the material thereof in a form having appreciable thickness for purpose of illustration;

FIG. 6 is a perspective view of an inverted modified form of tray showing a portion of the adhesively coated, relatively rigid stiffening member of chipboard or the like separated from the bottom of the tray to illustrate the application of the stiffening member just prior to use of the tray;

FIG. 7 is a sectional view through a portion of the modified form of tray shown in FIG. 6 and through a portion of the stiffening member coated with pressure-sensitive adhesive being applied to the underside of the adhesively coated plastic portion of the tray; and

FIG. 8 is a sectional view on the line 8-8 of FIG. 6 through a portion of the tray having a stiffening portion adhesively attached to the plastic portion.

Referring more particularly to the drawings, in which like numbers of reference are used throughout the several views, a tray 1 of the present invention has a shaped plastic portion 2 of relatively thin, thermoplastic material, such as a polyvinylchloride, polystyrene, polyethylene, polypropylene or other thermoplastic resinous material, and a stiffening member 3, preferably of chipboard or other stiff, lightweight material. The plastic portion 2 of the tray of the present invention may be formed in any desirable shape by the well-known vacuum-forming process. It is made from very thin gauge as an upstanding continuous outer rimi portion 4 surrounding the central bottom portion 5 to help retain food or articles on said bottom portion of the tray. The upstanding rim portion is of generally inverted U-shaped cross section and may have inner peripheral walls 4a, outer peripheral walls 4b joined by a crest portion 4c. An outer peripheral, flat horizontal flange portion 6 surrounds the outer peripheral wall 4b of the rim portion 4 and is integral with the outer wall 417.

The stiffening member 3 is a flat sheet of relatively lightweight or low density material, preferably chipboard or other porous, rigid solid. In accordance with the present invention means is provided for quickly attaching the flat stiffening member to the bottom of the formed or shaped plastic tray when the tray is to be used. The separable portions of the tray are each separate and stackable to occupy minimal volume until use.

In accordance with the modifications of FIGS. 1 to 6, inclusive, the means for quickly attaching the stiffening member 3 to the bottom of the tray comprises two inwardly opening channels, one of which is formed in part by and carried by a horizontal flange 6 on each of two opposite sides of the tray. The channels each have an inwardly directed opening 8, the upper wall of which is formed by the flange 6. The downwardly projecting wall 7 and the inwardly directed flange 9 cooperate with the flange 6 in forming each of the channels, which are of sufficient width to slidablly receive the two opposite edges of the flat stiffening member 3.

The shaped, upper plastic trays may thus be stacked to occupy minimal volume prior to use and when separated may be quickly assembled by sliding the stiffening member into place, as shown by FIGS. 1 and 2 of the drawing. The result is a lightweight, stiff, disposable tray having the stiffness of a heavy plastic tray but of minimal cost.

In the modifications of FIGS. 1 to 5, inclusive, the stiffening member 3 may be removed for reuse prior to disposing of the plastic portion 2.

Although I usually, prefer to make the stiffening member of chipboard, it may be of wood, plastic, etc. Since the stiffening member is reusable, it may obviously even have transverse and/or longitudinal stiffening ribs (not shown) of U-shaped cross section.

The article-receiving portion 1 of the tray is formed (usually vacuum-formed) from a thin sheet of vinyl resin or resin mixture, which vinyl resin is preferably rigid, unplasticized or only slightly plasticized polyvinylchloride copolymer of vinyl and one or more of vinylidene chloride, vinyl acetate, acrylonitrile and styrene, polystyrene (polyvinyl benzene), polyethylene, or polypropylene. The plastic article-receiving portion of the tray although having portions of somewhat reduced thickness caused by flow of material, being formed from a thin sheet, is of quite uniform thickness. It has insufficient strength to adequately support the articles being served until reinforced by the stiffening member 3.

In the modification shown in FIGS. 6 to 8 of the drawing, both stiffening member and the bottom of the tray are provided with a coating of a pressure-sensitive adhesive which has no tendency to adhere to uncoated surfaces such as paper, plastic, polyvinylchloride sheet and the like, but which adheres strongly to other similarly coated surfaces upon contact therewith.

Suitable suitable pressure-sensitive adhesive may be prepared in many suitable ways. Conveniently, it is prepared by mixing a large proportion of a resinous material, such for example as Koresin, which is a condensation product of a substituted phenol and acetylene, with natural or-synthetic rubbers. One such composition comprises 50 to parts of Koresin and 20 to 50 parts of an oil-extended rubber, which consists of parts ofa rubber of 100 to Mooney (large rotor) and 50 parts by weight of a high-boiling oil. This composition is dissolved in a suitable solvent for rubber and applied to the bottom surface of the plastic portion of the tray and to one surface of the stiffening member and allowed to dry by evaporation of solvent. If desired, the elements of the composition may be combined directly in solution.

In place of Koresin, various other resins such for example as thermoplastic aromatic hydrocarbon or styrenated hydrocarbon resins of petroleum origin may be used. Other solventsoluble synthetic rubbers and natural rubber may also be used in place of the oil-extended rubber in the manufacture of the adhesive. It is necessary, however, that the film of the resin be dried to the nontacky state and yet be highly adhesive to itself when dry.

In the modifications of FIGS. 6 to 8, the stiffening member 3a has its upper surface ill coated with a film of a suitable pressure-sensitive but nontacky adhesive, such as that described above. The entire lower surface of the tray, including the lower surface 12 of the flange 6a and the lower surface 13 of the central bottom portion of the tray are also coated with a film of the dry pressure-sensitive adhesive. Neither the stacked stiffening members nor the article-receiving portions of the tray adhere to east: other. However, when the tray is to be made ready for use, the stiffening member is quickly applied to the bottom of the tray by merely placing the adhesive coated surface of the stiffening member 3a against the adhesive-coated undersurface of the thermoplastic shaped portion of the tray, whereupon the stiffening member becomes integral with the remainder of the tray.

In the modified form of tray shown in FIGS. 6 to 8, however, the stiffening member cannot be conveniently again separated from the shaped plastic portion of the tray for reuse.

It is also apparent that in accordance with the provisions of the patent statutes modifications of the invention may be made without changing the spirit thereof.

lclaim:

1. A tray component suitable for quick assembly with a stiffening member to form a desirable tray suitable for serving food and articles to airplane passengers and the like, said component being of relatively uniform thickness and comprising an upstanding outer peripheral rim surrounding an articlereceiving bottom portion, upstanding portions of said rim comprising walls joined at their upper edges and being of generally inverted U-shaped cross section comprising inner and outer peripheral walls of equal height and diverging outwardly at their open side, whereby several of said components are stackable one above the other with upstanding portions of a lower tray component disposed in upstanding portions of an upper similar component, the outer peripheral walls of said inverted U-shaped rim having integrally formed at the lower edge thereof a flat horizontal, outwardly extending flange por tion, the lower surface of which is coplanar with a lowermost surface portion of said bottom, and means for quickly attaching a flat, separately formed stiffening member to said flange along at least two opposite sides of the bottom of the outer peripheral wall of the said outer peripheral rim of said component to bear against said bottom, whereby said peripheral rim and said bottom will each coact with said stiffening member to stiffen said tray.

2. A tray component suitable for quick assembly with a stiffening member to form a desirable tray suitable for serving food and articles to airplane passengers and the like, said component being of relatively uniform thickness and comprising an upstanding outer peripheral rim surrounding an articlereceiving bottom portion, upstanding portions of said rim being of generally inverted U-shaped cross section and comprising inner and outer walls joined at their upper edges and diverging outwardly on their open side whereby several of said components are stackable one above the other with upstanding portions of a lower tray component disposed in upstanding portions of an upper similar component, the outer peripheral walls of said inverted U-shaped rim having integrally formed at the lower edge thereof a flat horizontal, outwardly extending flange portion, the lower surface of which is substantially coplanar with a lowermost surface portion of said bottom, said flange at each of two opposite sides of said component having at the outer edge thereof a downwardly projecting wall which at the lower edge thereof has an inwardly extending flange, said flanges cooperating with said downwardly projecting wall and forming two channels having inwardly directed openings facing each other to slidably receive two opposite side edges of a separately formed flat stiffening member of sufficient size to span the space between said channels and enter therein, whereby said stiffening member will coact with both said outer rim and said bottom to stiffen said tray component.

3. A tray according to claim 1 wherein the lower surface portions of said flange and said bottom of the plastic component has thereon a film of nontacky, pressure-sensitive adhesive adapted to cooperate with and adhere to a film of non tacky thermoplastic adhesive on a stiffening element.

4. A tray according to claim 1 wherein the thermoplastic material is a vinyl resin.

5. A disposable tray suitable for serving food and the like to airplane passengers comprising two separately formed components, one of said components being an article-receiving component shaped of thin thermoplastic vinyl resin to a form to receive articles therein, and comprising an upstanding outer peripheral rim surrounding an article-receiving bottom portion, upstanding portions of said rim being of generally inverted U-shaped cross section and comprising inner and outer peripheral walls of the same height joined at their upper edges and diverging outwardly at the open side whereby several of said components are stackable, one above the other, with upstanding portions of a lower tray component disposed in upstanding portions of an upper similar component, the outer peripheral wall of said inverted U-shaped rim being downwardly extending and having integrally formed at the lower edge thereof an outwardly extending horizontal flange, the lower surface of which is coplanar with a lower surface portion of said bottom, another of said components being a generally flat stiffening component and being attached to said rim bearing against the bottom surface of said flange thereof and against said lower surface portion of said bottom portion, whereby said stiffening component coacts both with said bottom portion and with said rim and said flange thereof to stiffen the tray.

6. A disposable tray suitable for serving food and the like to airplane passengers comprising two separately formed components, one of said components being an article-receiving component shaped of thin thermoplastic vinyl resin to a form to receive articles therein, and comprising an upstanding outer peripheral rim surrounding an article-receiving bottom portion, upstanding portions of said rim being of generally inverted U-shaped cross section and comprising inner and outer peripheral walls joined together at their upper edges and diverging outwardly at their open sides whereby several of said components are stackable, one above the other, with upstanding portions of a lower tray componentdisposed in upstanding portions of an upper similar component, the outer peripheral wall of said inverted U-shaped rim being downwardly extending and having integrally formed at the lower edge thereof an outwardly extending horizontal flange, the lower surface of which is coplanar with a lower surface portion of said bottom, said flange at each of two opposite sides of said article-receiving component having at an outer edge thereof a downwardly projecting wall which at the lower edge thereof has an inwardly extending flange, said outwardly and inwardly extending flanges cooperating with said downwardly projecting wall to form two channels having inwardly directed openings along opposite sides of said article-receiving component, another of said components being a generally flat stiffening member of sufficient size to span the space between said channels and to enter the openings of said channels, whereby said stiffening member coacts with both said bottom portion and said rim through said flanges to stiffen said tray.

7. The tray of claim 5 wherein said stiffening element is of lower density than said article-receiving element.

8. The tray of claim 5 wherein one surface only of said stiffening component has a dried film of pressure-sensitive adhesive thereon and a lower surface of the article-receiving component has a dried film of cooperating adhesive thereon.

9. The tray of claim 5 wherein said stiffening element is chipboard. 

1. A tray component suitable for quick assembly with a stiffening member to form a desirable tray suitable for serving food and articles to airplane passengers and the liKe, said component being of relatively uniform thickness and comprising an upstanding outer peripheral rim surrounding an article-receiving bottom portion, upstanding portions of said rim comprising walls joined at their upper edges and being of generally inverted Ushaped cross section comprising inner and outer peripheral walls of equal height and diverging outwardly at their open side, whereby several of said components are stackable one above the other with upstanding portions of a lower tray component disposed in upstanding portions of an upper similar component, the outer peripheral walls of said inverted U-shaped rim having integrally formed at the lower edge thereof a flat horizontal, outwardly extending flange portion, the lower surface of which is coplanar with a lowermost surface portion of said bottom, and means for quickly attaching a flat, separately formed stiffening member to said flange along at least two opposite sides of the bottom of the outer peripheral wall of the said outer peripheral rim of said component to bear against said bottom, whereby said peripheral rim and said bottom will each coact with said stiffening member to stiffen said tray.
 2. A tray component suitable for quick assembly with a stiffening member to form a desirable tray suitable for serving food and articles to airplane passengers and the like, said component being of relatively uniform thickness and comprising an upstanding outer peripheral rim surrounding an article-receiving bottom portion, upstanding portions of said rim being of generally inverted U-shaped cross section and comprising inner and outer walls joined at their upper edges and diverging outwardly on their open side whereby several of said components are stackable one above the other with upstanding portions of a lower tray component disposed in upstanding portions of an upper similar component, the outer peripheral walls of said inverted U-shaped rim having integrally formed at the lower edge thereof a flat horizontal, outwardly extending flange portion, the lower surface of which is substantially coplanar with a lowermost surface portion of said bottom, said flange at each of two opposite sides of said component having at the outer edge thereof a downwardly projecting wall which at the lower edge thereof has an inwardly extending flange, said flanges cooperating with said downwardly projecting wall and forming two channels having inwardly directed openings facing each other to slidably receive two opposite side edges of a separately formed flat stiffening member of sufficient size to span the space between said channels and enter therein, whereby said stiffening member will coact with both said outer rim and said bottom to stiffen said tray component.
 3. A tray according to claim 1 wherein the lower surface portions of said flange and said bottom of the plastic component has thereon a film of nontacky, pressure-sensitive adhesive adapted to cooperate with and adhere to a film of nontacky thermoplastic adhesive on a stiffening element.
 4. A tray according to claim 1 wherein the thermoplastic material is a vinyl resin.
 5. A disposable tray suitable for serving food and the like to airplane passengers comprising two separately formed components, one of said components being an article-receiving component shaped of thin thermoplastic vinyl resin to a form to receive articles therein, and comprising an upstanding outer peripheral rim surrounding an article-receiving bottom portion, upstanding portions of said rim being of generally inverted U-shaped cross section and comprising inner and outer peripheral walls of the same height joined at their upper edges and diverging outwardly at the open side whereby several of said components are stackable, one above the other, with upstanding portions of a lower tray component disposed in upstanding portions of an upper similar component, the outer peripheral wall of said inverted U-shaped rim being downwardly extending and having integrally formed at the loweR edge thereof an outwardly extending horizontal flange, the lower surface of which is coplanar with a lower surface portion of said bottom, another of said components being a generally flat stiffening component and being attached to said rim bearing against the bottom surface of said flange thereof and against said lower surface portion of said bottom portion, whereby said stiffening component coacts both with said bottom portion and with said rim and said flange thereof to stiffen the tray.
 6. A disposable tray suitable for serving food and the like to airplane passengers comprising two separately formed components, one of said components being an article-receiving component shaped of thin thermoplastic vinyl resin to a form to receive articles therein, and comprising an upstanding outer peripheral rim surrounding an article-receiving bottom portion, upstanding portions of said rim being of generally inverted U-shaped cross section and comprising inner and outer peripheral walls joined together at their upper edges and diverging outwardly at their open sides whereby several of said components are stackable, one above the other, with upstanding portions of a lower tray component disposed in upstanding portions of an upper similar component, the outer peripheral wall of said inverted U-shaped rim being downwardly extending and having integrally formed at the lower edge thereof an outwardly extending horizontal flange, the lower surface of which is coplanar with a lower surface portion of said bottom, said flange at each of two opposite sides of said article-receiving component having at an outer edge thereof a downwardly projecting wall which at the lower edge thereof has an inwardly extending flange, said outwardly and inwardly extending flanges cooperating with said downwardly projecting wall to form two channels having inwardly directed openings along opposite sides of said article-receiving component, another of said components being a generally flat stiffening member of sufficient size to span the space between said channels and to enter the openings of said channels, whereby said stiffening member coacts with both said bottom portion and said rim through said flanges to stiffen said tray.
 7. The tray of claim 5 wherein said stiffening element is of lower density than said article-receiving element.
 8. The tray of claim 5 wherein one surface only of said stiffening component has a dried film of pressure-sensitive adhesive thereon and a lower surface of the article-receiving component has a dried film of cooperating adhesive thereon.
 9. The tray of claim 5 wherein said stiffening element is chipboard. 